Closure fastener



March 1952 c. BURGOYNE CLOSURE FASTENER Filed Feb. 13, 1950 INVENTOR.

Cf/HELEJ LEUEGOY/VE wad) AT 70,8415) t Patented Mar. 11, 1952 UNITED STATES PATENT OFFICE 4 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention describedherein may be manuiaotured and used by or for the United States Government for governmental purposes with out payment to me of any royalty thereon.

The present invention relates to a closure fastener or latch particularly intended for use on access panels and covers installed on aircraft, cabinets, junction boxes and miscellaneous enclosures.

The primary object of the invention is to provide a simple lever operated closure fastener having a maximum degree of security and reliability.

A further object of' the invention is to provide a lever operated closure fastener wherein the lever is used to project a spring retracted latch bolt and wherein the latch bolt functions in its projected position to not only retain a closure in closed position but to also secure the bolt projecting lever in the bolt projecting position thereof.

Another object of the invention is to provide a lever operated closure fastener wherein the lever is used to project a spring retracted latch bolt and wherein the latch bolt and lever become mutually interlocked in the bolt projected positions thereof and wherein means is provided to insert a thin rod through a portion of the leverto-cause the latch bolt to be projected beyond the normal projected position whereby the latch bolt and lever are placed in non-interlock ing conditionso that the latch bolt can be retracted upon rotation of the lever.

Another object of the invention is to provide a closure fastener having means requiring use of" a special tool to effect retraction of the latch bolt included in the closure fastener.

The above and other objects of the invention willrbecome apparent upon reading the following description in conjunction with the drawing, in which:

Fig. 1 is a central longitudinal cross sectional view showing the present closure fastener installedion a sheet metal door or panel with the fastener in the latched condition thereof.

Fig. 2 is a View similar to- Fig. l but showing the fastener in the unlatched condition.

- Referring to the drawing there is shown a fragmentary section of a sheet metal door or access panel 1 serving to close an opening in a surrounding sheet metal structure 2, which may also be termed the door frame. The door I is pivotally mounted on the door frame by means of" 9....(1001 hinge 3 having two associated leaves rigidly-secured to the door frame and door respectively. At the opposite or free swingingedge of the door there is mounted the closure fastener forming the subject matter of the present application. The adjacent sheet metal frame structure is provided with a strengthening angle bar 4 adapted to form a latch bolt engaging member or keeper.

The closure fastener includes three principal components or elements, namely the channel shaped casing 5, the sliding latch bolt 6 and the camming lever l for projecting the spring retracted latch bolt to the latched position as shown in Fig. 1.. The casingfi includesoppositely extending coplanar flanges 8 for use in attaching the casing and elements carried therein to the inside surface of the door I. No particular attaching means is shown but it is understood that any suitable means may be employed; such as spot welding at several points-along thelength of the flanges. The channel shaped passage through the casing, preferably of. square or rectangular cross se'ctionalshape, accommodates the sliding latch bolt 6 which is recessed through a major portion of its length, as at 9, to receive a spring abutment it secured to the door land to receive a compression spring H extending between the abutment NJ and a portionof the bolt 6. In the latched position of bolt 6. as in Fig. 1; the spring I! is under compression so that its expensive force is available to'move the'latch bolt to retracted position (Fig. 2), when the position of the camming lever l permitssuch retraction. The bolt includes a rearwardly projecting lug or detent l2 adapted to engage a portion of the camming lever and retain the lever in; the bolt projecting position. The upper rearward corner of this lug is preferably rounded off slightly for smoother action with the cam portion of lever I. It will also be noted that the bolt ii is beveled off at It to provide a door tightening action by its engagement with the keeper 4. The latch bolt 6 is of uniform Width. throughout and is guided in its reciprocating movement by the 0pposite side walls of channel shaped casing 5.

The camming lever I having the same width as the latch bolt fits nicely into the bolt casing and includes a finger engageable lever or handle portion l4 having finger grip recesses 55 at opposite sides thereof. A rectangular opening IS in the door I allows free swinging movement of the camming lever and the lever is mounted for pivotal movement on a pivot l1 extending through the opposite side walls of the casing 5 and riveted thereto. The camming" lever is provided with stepped formations at" two spaced apart points, to provide a first shoulder portion l8 engaged by the detent l2 in the bolt projected position and a second shoulder portion l9 engaged by the detent l2 in the bolt retracted position. Between the shoulders 68 and E9 the lever is provided with a cam portion 28 of gradually varying radius, with respect to the lever pivot ll. Extending through the lever i along the central plane thereof is a bolt releasing bore or passage 2i adapted to receive a thin rod or nail for releasing the bolt from the lever and thus permitting bolt retracting movement of the lever, so as to finally bring the parts of the closure fastener to the position as shown in Fig. 2.

The latched position as shown in Fig. 1 results when the lever l is brought to a position in which the handle portion [4 contacts the outer surface of the door I and the lug or detent portion I2 of the bolt 6 engages the shoulder It on the lever i. In this position the latch bolt is positively retained in the projected position by the lever l and the lever is prevented from rotating by the engagement of the bolt and shoulder l8. As may be seen the bolt retracting spring acts to maintain the bolt in th s lever locking relation.

If it is desired to unlatch the door I it is merely necessary to insert a thin rod into the aperture 2! in lever l and exert enough force thereon to project the bolt beyond the normally latched position. When the bolt has been projected far enough to clear the shoulder IS, an upward lift on the handle portion is is effective to move the lever l to the position of Fig. 2. Of course the bolt projecting rod must be removed from the passage 2| just after the lever has been freed from the bolt lug l2. Upon movement of the lever I to the unlatched position, the bolt.

retracts under the pressure of spring l l while the lug l2 follows the lever cam portion 26. When the bolt is fully retracted the second shoulder l 9 on the lever 7 contacts the bolt lug I2 and the movable parts are maintained in the positions shown in Fig. 2. It is noted that the bolt retracting movement of the camming lever l is assisted by the spring retracted bolt pressing on the cam formation between shoulders l8 and IQ. To latch the door I it is first closed and then the lever l is rotated counterclockwise from the position of Fig. 2. The cam portion 2!! of the lever 1 acts to gradually project the latch bolt 6. Finally the handle portion I l contacts the door surface at the same time the bolt lug l2 snaps into place above the shoulder 58 (Fig. 1).

The principal advantages of the present closure fastener are:

(1) The inherent security in the door latching position, brought about by the mutual locking engagement of the latch bolt and lever.

(2) The impossibility of unlatching the fastener except by use of a simple tool manipulated in a definite manner. Thus is will be seen that the latch is not responsive to any sort of manipulation or pressure to become unlatched, except of coarse the special manipulation described above. The added security will mean that the device can be depended on to hold the door closed until the proper tools and manipulation are combined to efiect unlatching of the device.

The embodiment of the invention herein shown and described is to be regarded as illustrative only and it is to be understood that the invention is susceptible of variations, modifications and changes within thescope of the appended claims.

I claim:

1. A closure fastener comprising, a casing having a channel-like passage extending therethrough, a latch bolt movably mounted in said casing, spring means in said casing for biasing said latch bolt toward the retracted position Within said casing, a carnming lever having one end portion pivotally mounted in said casing adjacent to said latch bolt and having the other end extending from said casing to form a handle element, flange means on said casing for mounting said closure fastener on the inside surface of a closure with said handle element extendin through an opening in said closure for manipulation from the outside of said closure, a cam portion on said lever at the pivoted end thereof to project said latch bolt to the projected position upon rotation of said lever in one direction until said handle element contacts the outside of said closure, shoulder means on said camming lever at one end of said cam portion facing toward said handle element and engageable by an extending portion of said latch bolt in the projected position thereof to retain said lever in stationary position after it has been rotated in said one direction to project said latch bolt, and said camming lever having a transverse passage therethrough opening at one end adjacent to said shoulder means for reception of a rod to exert pressure on said latch bolt in the normal projected position and thus move said latch bolt beyond the normal projected position to cause disengagement of said shoulder means and said extending portion of said latch bolt.

2. A closure fastener comprising, a casing havlllg a channel-like passage therethrough, a latch bolt reciprocably mounted in said casing and having one end adapted to project from said casin in the projected position of said latch bolt, spring means in said casing for biasing said latch bolt toward the retracted position within said casing, a camming lever having one end portion pivotally mounted in said casing adjacent to the other end of said latch bolt and extending from the casing to form a handle element, a rigid detent element on said other end of said latch bolt extending toward the pivoted end portion of said camming lever and having a flat shoulder facing away from said handle element in the bolt projected position of said camming lever, a cam portion on said lever at the pivoted end portion to project said latch bolt to the projected position on rotation of said lever in a direction to move said handle element toward said latch bolt, and means providing a fiat shoulder on said camrning lever at one end of said cam portion and facing toward said handle element for face-to-face engagement by the flat shoulder of said detent element after said camming lever has been rotated in a bolt projecting direction far enough to pro ject said latch bolt and to bring the flat shoulders of said camining lever and detent element in alignment, whereupon said spring means causes sufficient retracting movement of said latch bolt to elfect said face-to-face engagement and thereby positively prevent movement of said camming lever in a bolt retracting direction.

3. A closure fastener comprising, a casing having a channel-like passage extending therethrough, a latch bolt movably mounted in said casing, spring means in said casing for biasing said latch bolt toward the retracted. position within said casing, a camming lever having one end portion pivotally mounted in said casing-adjacent to said latch bolt and having the other end extending from said casing to form a handle element. a cam portion on said lever at the pivoted end thereof to project said latch bolt to the projected position upon rotation of said lever in one direction, shoulder means on said camming lever at one end of said cam portion, a detent portion on the latch bolt at the end adjacent to said cam portion and engageable by said shoulder means in the projected position of said latch bolt to prevent movement of said camming lever in a bolt retracting direction, and said camming lever having a transverse passage therethrough opening at one end adjacent to said shoulder means for reception of a rod to exert pressure on said latch bolt in the normal projected position and thus move said latch bolt beyond the normal projected position to cause disengagement of said shoulder means and said detent portion of said latch bolt.

4. A closure fastener comprising, a casing hav ing a channel-like passage therethrough, a latch bolt reciprocably mounted in said casing and having one end adapted to project from said casing in the projected position of said latch bolt, spring means in said casing for biasing said latch bolt toward the retracted position within said casing, a camming lever having one end portion pivotally mounted in said casing adjacent to the other end of said latch bolt and extending from the casing to form a handle element, a rigid detent element on said other end of said latch bolt extending toward the pivoted end portion of said camming lever and having a flat shoulder facing away from said handle element in the bolt projected position of said camming lever, a cam portion on said lever at the pivoted end portion to project said latch bolt to the projected position on rotation of said lever in a direction to move said handle element toward said latch bolt, means providing a fiat shoulder on said camming lever at one end of said cam portion and facing toward said handle element for face-to-face engagement by the flat shoulder of said detent element after said camming lever has been rotated in a bolt projecting direction far enough to project said latch bolt and to bring the flat shoulders of said camming lever and detent element in alignment, whereupon said spring means causes sufficient retracting movement of said latch bolt to effect said face-to-face engagement and thereby positively prevent movement of said camming lever in a bolt retracting direction, and means for reception of a rod to exert pressure on said latch bolt in the normal projected position and thus move said latch bolt beyond the normal projected position to cause disengagement of said flat shoulders of said. camming lever and detent element.

CHARLES L. BURGOY NE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 477,801 Hayes June 28, 1892 686,166 Taylor Nov. 5, 1901 FOREIGN PATENTS Number Country Date 564,476 France Oct. 20, 1923 688,595 Germany Feb, 24, 1940 

